1. Field of the Invention
The present invention relates to a turbine wheel for a turbine engine, such as an aircraft jet engine or turboprop provided with such a wheel. It also relates to a sealing and vibration damping member intended to be used with a turbine wheel and a turbine engine, as mentioned above.
2. Description of the Related Art
A wheel 10 of a high pressure turbine in a turbine engine, as shown in FIG. 1, comprises a disc 14 carrying blades 16 regularly distributed around the wheel axis and the roots 18 of which are engaged into substantially axial slots of the periphery of the disc 14. The blade roots 18 may be of the fir tree or dovetail section type, and the grooves in the disc 14 have shapes that match those of the blade roots 18 and define teeth or ribs 20 between them.
Each blade 16 comprises an impeller 22 the radially inner end of which is connected to a platform 24, which is itself connected to a root 18 by a stilt 26.
The upstream end and the downstream end of each platform 24 are respectively connected to an upstream radial wall 30 extending radially inwards and to a downstream radial wall 28 extending radially inwards.
In mounting position (FIGS. 1 and 2), the platforms 24 of the blades 16 are circumferentially arranged end-to-end so as to form an inner annular wall for the flowing of primary air from a combustion chamber. Similarly, the upstream 28 and downstream 30 radial walls are arranged opposite each other on the circumference.
Mounting sealing and vibration damping members 32 into inter-blade cavities is known. More particularly, each inter-blade cavity is defined radially outwards by the inner faces of two platforms 24 positioned opposite each other on the periphery, radially inwards by a rib 20 of the disc 14, axially by two transverse upstream 30 and downstream 28 radial walls, the ends of which are positioned opposite each other on the periphery, and circumferentially by the stilts 26 of the blades 16.
Each sealing and vibration damping member 32 is mounted into a cavity and held in position therein by pins 34 protruding in the cavity. In a first known embodiment (FIG. 2), the upstream radial wall and the downstream radial wall of each blade each comprise a pin 34 which radially holds the member 32 inwards, on one side of the stilt 26. In another embodiment, each stilt 26 of a blade comprises a pin 34 on each one of its side faces.
Such pins 34 thus form supports for the members upon stopping of the turbine engine and when mounting the members 32 into the cavities. However, in operation, centrifuge force presses the members 32 against the platforms 24 so that the pins 34 no longer have a holding function.
To reduce the weight of the turbine wheel, omitting the pins 34 mentioned above would be interesting, while ensuring the holding in position of the members 32 upon stopping of the turbine engine and an easy mounting of the members 32 into the cavities.